This invention relates to optoelectronic functional circuits, and more particularly to a diode laser amplifier used to perform clocked optical pulse regeneration, external modulation, and selective optical channel read-out.
The transmission of optical pulse signals through various optical media such as fibers or air causes both attenuation and pulse distortion due to dispersion of the pulses in the media. In order to maintain the signal amplitude at a satisfactory level, optoelectronic regenerative repeaters are required between fiber spans. Regenerators restore a weak and distorted signal to a large signal of original state. In present optical regenerator circuits, the optical signal is first converted to the electrical domain, amplified, and by clock recovery, retimed and converted back to the optical domain by modulating a transmitting semiconductor laser. Disadvantageously, the speeds of such electrical regenerators are constrained by the characteristics of the electrical components, the speeds of which are limited below those of present optical processing components. Furthermore, the optoelectric and electrooptic conversion introduce additional distortion to the signal.
An object of the present invention is to regenerate digital signals in an optical transmission system in the optical domain.
An additional object of the present invention is to optically regenerate the digital signal in a way that restores the signal to its original signal level, removes the pulse distortion, and reshapes the output pulses.